Sewing machine



Jan. 15, 1929. 1,699,354

' C. H. GREENWOOD' SEWING MACHINE Original Filed March 2, 1925 3 Sheets-Sheet l IIIIlIIIIIII/IIIIIIII K l IIIIIIIII'IIIIIIIIIIIIIII fill/Ille A vr vllrgllgllll In wauw. *wie* lllllllll Zai 'IIIIIIIIIIIIIIIIIIIIIIIII NL, /Y/e/zwmd JAM Gramm@ Jan. 15, 1929.

C. H. GREENWOOD SEWING MACHINE 5 Sheets-Sheet 2 Original Filed March 2. 1923 c. H. GREENWOOD .I an. 15, 1929.

SEWING MACHINE t im m 0 w. s w .i N Mw Patented Jan. l5, 1929.

CHARLES H. GREENWOOD,

PATENT OFFICE.

F BELVIDERE, ILLINOIS.

SEWING MACHINE.

Application led March 2, 1923, Serial No. 622,306. Renewed .Tune 14, 1928.

This invention relates to sewing machines and more particularly 'to improvements in the feed and rotary hook and driving means for the same.

The objects of the invention are to provide a simple and positive driving mechanism for operating both the rotary hook and the feed to so construct the rotary hook and arrange the location of the same with reference tov t-he feed and the needle as to produce a smaller loop; to provide a hook and bobbin case of such construction that the bobbin may be placed either end up in the bobbin case without .aectingA the tension upon the lower thread; to provide means for permitting the bobbin to 'be easily lifted from the bobbin .case without requiring a bobbin ejector; to provide means for causing a self threading of the lower or bobbin thread through the tension upon the bobbin case; to provide a simple and easily operated stitch adjusting mechanism cooperating with the feed drive; to provide suitable means for keeping the Working parts of the mechanism lubricated and to generally improve and simplify mechanism of this character; and to provide ama'- chine which is practically fool proof.v

rlhe above and other objects may be attained by constructing the mechanism in the manner illustrated in the accompanying drawings, in Which- Figure 1 is a vertical, longitudinal, sectional view through a sewing machine embodying the invention;

Fig. 2, a plan sectional view approximately on the line 2 2, Fig. l;

Fig. 3, a section on the line 3 3, Fig. 2;

Fig. 4, a section on the line 4 4, Fig. 2; Fig. 5, a section-on the line "5 5, Fig. 2; Fig. 6, a section on the line 6 6, Fig. 2; Fig. 7 a plan view of the needle plate; Fig. 8, an edge view of thesame; Fig. 9, a plan view of the rotary hook and bobbin case;

Fig. 10, a vertical sectional view through the same; v

Fig. 11, a sectional view through the needle plate;

Fig. nism; Fig. 13, a side elevation of the same; 1 Fig. 14, a section on the line 14 14, Fig. 12; and

Figs. and 16, side elevations of the eccentric mechanisms for operating the feed dog.

Similar numerals of reference indicate cor- 12, a plan view of the tension mechaing from the under side of the base-plate,

bushings 11 being provided in saidbearingS.

A-hollow shaft 12 is journaled at its opposite end portions within the bearings 13 and 14 formed in the depending walls 15` and 16 respectively, which are preferably formed integral with the base plate 3. A sleeve 17'is xed in the forward end of the tubular shaft 12 as by a screw 18 or the like, and a similar sleeve 19 is fixed in the rear end of the tubular shaft as by the screw 20.

A shaft 21 is journaled at opposite ends in the sleeves 17 and 19 and is provided at its rear end with aI bevel gear 22 which meshes lwith a similar gear,23 fixed upon the lower endof the shaft- 8.

A bevel gear 24 is ixed upon the forward end of the shaft 21 and meshes with the bevel pinion 25 upon thelower end ofthe spindle 26 of the'rotary loop taker 27, said spindle being journale'd in a suitable bearing 28 pro vided upon the transverse wall29 which depends from' the base plate 3. The gear 24 is prefei ably larger than the pinion 25.

For the purpose of keeping all of the above mentioned bevel gears properly lubricated, oil cups or wells 3() are located@x at suitable points adjacent to the gears and provided with wicks 31 engaging the tooth surfaces of one gear of each set.

A thin film of oil will thus be formed upon each of the gears .which contacts with one of the wicks and the cooperating gear of each set will also be properly7 oiled as it rotates in mesh therewith. ,f The interior of the hollow shaft 12 also constitutes an oil well for properly oiling'the-bearings of the shaft 21 and the parts associated therewith, an oil hle being provided in the hollow shaft .12 .for filling said Well.

f 'An armV 32 is xed upon the sleeve 19 and extends outward through a slot 33 in the casing, 34 which is connected to the base plate and covers the'mechanism. An adjusting v screw 35 is journaled through an openinefy 36 in the base plate and provided with the enlarged, knurled head 37. The screw is reduced as at 38 to receive the bifurcated plate 39 mounted upon the under side of the base plate and connected thereto as by the screw 40.

It will thus be seen that the screw is journaled in the base plate and may be rotated in either direction by means of the knurledA head, without raising or lowering the screw in its bearing and without permitting the screw to be withdrawn, excepting upon removal of the bifurcated plate 39.

A nut 41 is mounted upon the threaded portion of the adjusting screw and provided with| a radial flange 42 carrying a pin43 which is extended through the elongated slot 44 in the arm 32. rllhus by rotating the screw to raise or lower the nut 41, the sleeve 19, and through it the hollow shaft 12 and sleeve 17 will be rocked in unison.

The gear 24 is provided with the enlarged hub portion 45 upon which is keyed or'splined a pair of eccentrics 46and 47. An eccentric Vband 48 is journaled upon the eccentric 46 and provided" with an upwardly extending arm 49 to which the Jfeed dog 50 is connected as bythe screw 51, said arm having `a horizontally disposed portion 52, the end portion of which is slidably located within the guide 53 which is formed upon the under side ofv the base plate.

An eccentric band 54 is mounted upon the eccentric 47 and provided with the tangential rearwardly disposed arm 55,. the end portion of which is slidably mounted in the guide 56 provided upon the bottom wall of the casing 34. A link 57 is connected at its lower end to the arm as by the pin 58, the upper end of the link being pivotally connected to a stationary portion of the machine, such a the wall 29 as by the pin 59.

A" pair of slotted links 60 are connected at their upper ends to the arm 52, one of said links being mounted upon each side of the arm. and a4 in 61 lixed in the upper ends of the two -lin rs extending through the vertical slot 62 in the arm 52. 'llhe lower ends of the links 60 are connected to the arm 55 by the pin 58 which connects said arm to the link 57.

A. bent arm 63 is xed upon the sleeve 17 and the end portion thereof is located between the links 60 and provided with a pin 64 located in the arcuate Grooves 65 formed in the links 60, this pin torming a fulcrum upon which the links 60 are rocked by the eccentric movements of the arms 52 and 55 to cause the feed dog 50 to move upward, forwardhdolwnward and backward in succession through the slots 66 in the needle plate 67.

In order to change the length of .the stitch, the adjusting screw 35 is adjusted 'as above described, rocking the arm 32 upon the sleeve 19, which in turn rocks the tubular shaft 12 and the sleeve 17 the arm 63 thereon being rocked, changing the fulcrum point 64 providing for a longer or shorter horizontal movement of the feed dog 50.

- The cup shaped body portion 27 of the loop taker is provided with the inwardly disposed, annular rim 68 exten-ding substantially around the same to engage the annular'groove 69 in the supporting plate 70 of the bobbin case 71. One half of this rim is removable as shown at 72 and preferably comprises the upper and lower spaced plates 72 and 73 between which is located a sheet of felt or the like 74, the lower plate 73 being provided with one or more openings 75 communicating with the oil well 76 formed in the body portion 27,

thus providing lubrication to the groove 69 tionary hook 81 which catches the lower part of the needle loop for detention in the opening 80 until said loop has been carried about the bobbin case and the loop detaining shoulder 78 has reached the cut away extension 80 of said opening 80, to permit escape of the needle loop. This cut away 80.'x11 provides means for quickly releasing the loop which is a desirable feature in sewing machine construction.

The bobbin case or thread case 71 comprises an open ended cylinder formed integrally with or lixedly mounted upon the supportingplate 70 and having the inwardly disposed, annular flange 82 at its lower end to support the bobbin. l

A lu 83 is provided upon the the bobin case at a point adjacent to the opening 80 andvarranged to be,received within a notch 84 formed inthe downturned flange 85 of the needle plate, thus preventing rotation of the bobbin case, while the circular loop taker and hook may freely rotate around the same.

The supporting plate 70 is provided withy the cut-out portion 86 within which is mounted the tension comprising the curved block 87 which is spot welded or otherwise connected to the wall of the bobbin case and provided with the enlarged head portion 88 having the curved under edge 89, the forward end thereof being also curved as at 90, terminating in the point 91, spaced from the bobbin case as shown at 92.

A vert-ical slot 93 is formed in the wall of the bobbin case in alignment with the dat end 94 of the block 87 and a, spring 95, curved outer edge ofk lll downward along itsv edge as shownl at 96 and the underside of the head as by the screw 98.

It will be noted that the under side of the head 88 is inclined upwardly away from the slot 98, as shown at 99, the spring 95 forming therewith an upwardly inclined passage for the bobbin thread arranged to direct the thread toward the needle opening 100 inthe needle plate 67. lt will be seen that the upper edge of the bobbin case adjacent to the point 91 is cut away for a considerable distance from the slot 93 as shown at 101 and a somewhat similar cut-out 102 is formed in the diametrically opposite side of the bobbin case to permit the operator to insert the thumb and finger nails beneath the upper flange of the bobbin to remove the same from the bobbin case, without requiring the use of the usual bobbin ejector. The cut-out 101 also provides a thread guide to guide the thread from the bobbin into the' slot 93 and between the spring 95 and head 88 of the tension'- The bobbin may be placed in the bobbin case in either position and the loose end ofthe thread thrown over the cut-out portion 101 of the bobbin case.

As the needle loop passes around the bobbin case, it will take up this loose end ofthe bobbin thread and carry'the same under the point 91 of the head 88 and through the slot 93 of the bobbin case, pulling the end of the thread up between the spring 95 and head 88 of the tension, directing the extremity of the thread# toward the needle opening in the needle plate. It will thus be seen that the bobbin case is self-threading, as well as being operative with the bobbin in either position.

In vrotary hook machines it is of course necessary to hold the bobbin case against roation with the loop taker. This requires the engagement of some point upon theV bobbin case with a stationary 'portiony of the machine, ,and each time the loop is .carried around the'bobbin cas'e the thread is pinched at this point, often causing sla-ck thread to be drawn out after the complete loop is taken.

The take-up will not take care of this eXtra slack in the thread and it is customary to increase the tension upon the needle thread to prevent this slack in the loop, but in sewing thin material a heavy tension causes the material to pucker.

In my construction, the bobbin caseis held against rotation by the ylug 83 engaging the notch 84 of the needle plate, and this lug is so located with reference to the hook that the pinch will come at the beginning of the formation of the loop. Thus if any slack thread is drawn out by this pinch, the same will be taken up by the hook and a much lighter tension may thus be used.

By'doing away with the usual bobbin-'ejector, which is ordinarily necessary with the horizontal loop taker, the diameter of the bobbin supporting plate is considerably reduced. Since the loop seizing hook projects inwardly, toward the bobbin case, the loop which is formed around the bobbin case is considerably smaller than is possible with the usual form of machine having a bobbin ejector.

The loop is further reduced in size by locating the bobbin case as close as is possible to the needle, as illustrated in the` drawings, there being only sufficient space to permit removal of the bobbin from the bobbin case without interference by the needle plate.

With this construction, the circular loop the usual construction and the bobbin is located closer to the needle as best illustrated in Fig. 10, thus forming a smaller needle loop.

It will be seen from the above that the driving mechanism for raising and carrying the feed dog is located directly beneath the feed, providing a positive, easy drive which may be easily and readily adjusted for different length of stitch by merely changing the location of the fulcrum 64 through'the adjusting screw of the stitch adjusting mechanism.

Regardless of the adjustment of the feed mechanism by means of the stitch adjusting device, the feed dog will always move-toward the front or operators sidel of the needle plate to a point almost contacting with the adjacent edge of the slot therein, thus obviating the possibility of catching the material between the feed dog and the edge of the slot taker may bey considerably smaller than in l drive mechanism for the dog including the Y links with the arcuate slots 65 in which the fulcrum 611s adjustable. The slots 65 form the arc of a circle, the center of which is at the center of the shaft 12, upon which the rocker arm 63 is fixed, when the feed dog is at the forward extent of its movement.

Thus by moving the fulcrum 6,4 to any point in the slots 65, the movement of the feed dog is lengthened or shortened, but the forward end of the travel of the feed dog always remains at the same point.

The rear end of the feed dog will be tilted slightly upward as the feed dog moves up to grasp the material and as it reaches its uppermost position, it will assume a hor1zon.

tal position. The forward end of the feed dog will thus be inclined slightly downward,

forming an open throat between the same and the pressure foot, facilitating the entrance of heavy seams between the feed dog and pressure foot.

The loop taker extending beneath the feed dog will tend to prevent lint from being deposited upon the gears and the bearings of the feed driving mechanism. To further assure the carrying ofthe lint away from these parts,

arm 49 and guides the lint away from a curved guard plate 104 is connected to the these parts.

I claim p K 1. In a sewing machine, a rotary shaft, a pair of eccentrics mounted upon the shaft, an eccentric band upon each eccentric, an upwardly disposed arm upon one band, a feed dog upon the upper end of said arm, a rearwardly disposed arm upon the other band, a link pivoted at its lower end to the rearwardly disposed arm and loosely connected at its upper end to the upwardly extending arm` and a fulcrum intermediate the extremities of said link.

2. In a sewing machine, a rotary shaft, a pair of eccentrics mounted uponthe shaft, an

eccentric band uponeach eccentric, an upwardly disposed arm upon ione band, a feed dog upon the upper end of said arm, an outwardly disposed arm upon the other band, a

link pivoted at its lower end to the outwardly disposed arm and loosely connected at its upper end to the upwardly extending arm, a fulcrum intermediate the extremities of said link, and means for changing the position of the fulcrum to change the length of movement of the feed dog.

3. In a sewing machine, a rotary shaft, a pair of eccentrics mounted upon the shaft, an eccentric band upon each eccentric, an upwardly disposed arm upon one band, a feed dog upon the upper end of said arm, an outwardly disposed arm upon the other band, a link pivoted at its lower end lto the outwardly disposed arm and loosely connected at its upper end to the upwardly extending arm, said link having an arcuate slot therein, a tubular rocker shaft journaled upon said rotary shaft, a rocker arm uponsaid rocker shaft, a pin upon the rocker arm extending into said arcuate slot and means for rocking said c rocker shaft and holding it in adjust-ed position.

4. In a sewing machine, a rotary shaft, a pair of eccentrics mounted upon the shaft, an eccentric band upon each eccentric, an upwardly disposed arm upo one band, a feed dog upon the upper end of saidarm, an outwardly disposed arm upon the other band, a link pivoted at its lower end tor the outwardly disposed arm and loosely connected at its upper end to the upwardly extending arm, said link having an arcuate slot therein, a tubular rocker shaft journaled upon said rotary shaft, a rocker arm upon said rocker shaft, a pin upon the rocker arm extending into said arcuate slot, and an adjusting screw for rocking said rocker shaft an holding it in adjusted position.

5. In a sewing machine, a rotary shaft, a/ pair of eccentrics mounted upon the shaft, an eccentric ban-d upon each eccentric, an upwardly disposed arm upon one band, a feed dog upon the upper end of said arm, a rearwardly disposed arm upon the other band, a link pivoted at its lower end to the rearwardly disposed arm and loosely connected at its upper end to the upwardly extending arm and a fulcrum intermediate the extremities lof said link, and guide means for said arms.

6. In a sewing machine, a rotary shaft, a pair of eccentrics mounted upon the shaft, an eccentric band upon each. eccentric, an' upwardly disposed arm upon one band, a feed dog upon the upper end of said arm, a rearwardly disposed arm upon the other band, a link pivoted at it-s lower end to the rearwardly disposed arm and loosely connected at its upper end to the upwardly extending arm and a fulcrum intermediate the extremities of said link, and a swinging support for the rearwardly extending arm.

.7. In a sewing machine, a rotary shaft, a pair of eccentricsy mounted upon the shaft, an eccentric band upon each eccentric, an upwardly disposed arm upon one band, a feed dog upon the upper end of said arm, a rearwardly disposed arm upon the other band, a link pivoted at its lower end to the rearwardly disposed arm and loosely connected at its upper end to the upwardly extending arm and a fulcrum intermediate the extremi-v ties of said link, and a link connected at its upper end to a stationary portion of the machine and at its lower end to disposed arm.

In, testimony that I claim the above, I have hereunto subscribed my name.

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